Today, due to the serious personal, social and economic burden caused by overweight and obesity, experts agree that policy interventions using the best available evidence is a necessary course of action. As a result, numerous national, state and local efforts have targeted school settings for obesity prevention policies. One fundamental knowledge gap to be addressed is whether these policy efforts directed at schools are effective. Another is identifying the extent to which states with strong policies also have districts and schools with strong policies. A team of investigators representing expertise in school nutrition and activity interventions, alcohol and obesity policy research and innovative methodologies propose aims that build upon recently published work linking state-level school obesity prevention policy environments and youth obesity prevalence which has received national attention. An advisory panel consisting of national and local advocacy and policy development experts will assist in the practical interpretation and dissemination of results. A serial cross-sectional study (1998-2010) that uniquely combines two survey data sets the Minnesota School Health Profiles and Minnesota Student Survey representing up to 300 schools and up to 136,00 12-18 year old students will be used to evaluate the impact of school nutrition- and activity-related policies upon students attending those schools. Additionally, using the national data set the School Health Programs and Policies Study a serial cross-sectional study (2000-2010) evaluating the translation of strong state policies (n=50) and their school districts (n=530) and schools (n=1,100) to identify the extent to which they align, will also be conducted. Tackling the childhood obesity epidemic demands innovative approaches, including environmental and policy changes in school settings. State and local entities have already engaged initiatives based upon varying levels of evidence. In the field of school policy evaluation, the emphasis has been on comprehensive wellness policy assessments, including the strength of those policies and implementation. To our knowledge, no one else has attempted to establish a link between school policy environments and student outcomes.